A Giant Hole Just Opened Up In A Sleepy Farming Town In Brazil

A hole suddenly appeared in a small farming town in Brazil.Press Release / Coromande

Residents in the sleepy farming town in Brazil were surprised to see a massive hole suddenly appear in the middle of a local soybean farm. The crater measured about 65 feet wide, while locals were unable to determine the depth of the funnel-shaped hole.

The town where the crater appeared is Coromandel, in the State of Minas Gerais, Brazil. The municipality of some 28,000 people thrives primarily on coffee, soybean, and corn agriculture. The region is also known for mining of its pure calcareous limestone rock, a likely culprit of the crater which recently formed.

Location of the collapsed hole in Coromandel.Google Maps

Geologists from the Federal University of Uberlândia visited the crater to study the cause and concluded that the hole is likely a sinkhole caused by the dissolution of the underlying bedrock. Similar to what is commonly seen in Florida, where limestone bedrock spans most of the state, Coromandel also sits on top of susceptible limestone.

The process by which sinkholes occur is natural and can create impressive karst topographies like those seen in southeastern Asia. Below is a photo of an extreme example where more of the ground has "sunken in" than remained, thus the pinnacles are regions where the ground has not yet collapsed due to a sinkhole.

Karst topography in ThailandPixabay

Rain is slightly acidic and when it falls. As it percolates into the ground it can, over time, dissolve calcium carbonate into calcium, carbon dioxide, and water.

CaCO3(s) + 2H+(aq) → Ca2+(aq) + CO2(g) + H2O (l)

This is the reason most sculptors do not use limestone to carve, as the statues won't stand the test of time the same way marble does. As the limestone (calcium carbonate) dissolves it leaves voids underneath the ground and eventually the overlying weight of the sediment causes the area to collapse. This collapsed feature is a sinkhole.

Sinkhole in the town of Coromandel, BrazilPress Release / Coromande

While the local farmers had not experienced this event happening in the area, it is an expected occurrence given the underlying bedrock. As this was not a common sight to locals, some attributed the cone-shaped hole to be a meteorite impact.

However, local professors ruled out the potential cause as a meteorite impact, stating "The impact of a meteorite is also ruled out because if there were, the earth would be thrown out and not have been swallowed, as it happened".

The area has since been isolated, preventing people and cattle from falling in and getting hurt. Professors noted that a local tourist attraction, the "Poço Verde/Green Well" is likely an old sinkhole that has since turned into a small lake.

I am a geologist passionate about sharing Earth's intricacies with you. I received my PhD from Duke University where I studied the geology and climate of the Amazon. I am the founder of Science Trends, a leading source of science news and analysis on everything from climate...